SELF-INITIALIZING ON-CHIP DATA PROCESSING APPARATUS AND METHOD OF SELF-INITIALIZING AN ON-CHIP DATA PROCESSING APPARATUS

摘要

An on-chip data processing apparatus has an operating supply voltage selected from a range of supply voltages and has voltage level detection circuitry configured to determine the level of the operating supply voltage. The voltage level detection circuitry comprises adaptive circuitry responsive to a variation in the reference voltage. Phase lock loop circuitry is configured to generate a source clock signal from the operating supply voltage, to receive the voltage level selection signal, to select a target frequency for the source clock signal in dependence on the voltage level selection signal, and to phase lock the source clock signal on the target frequency. Initialization circuitry is configured to initialize the on-chip data processing apparatus for data processing in dependence on the level of said operating supply voltage after the phase lock loop circuitry has phase locked the source clock signal on the target frequency.